Switch mechanism ensuring the automatic closing of a motor-operated garage door

ABSTRACT

The mechanism comprises two switches: a first thermostatic switch consisting of three successive adjacently spaced bimetallic blades; and a second switch having its contacts opened or closed by a first of said three blades. Movement of this first blade is caused by the passage of a motor-operating current through a heating element mounted on the first blade. The second switch is connected to the latching relay coil in the garage door motor circuit and its actuation, after the garage door has travelled to a fully opened position, ensures the automatic return of the garage door to a closed position. This mechanism enables the garage door to always close after it has been opened and also to give indication of its imminent closure.

United States Patent 1 1 Lafontaine 1 June 3,1975

[ SWITCH MECHANISM ENSURING THE AUTOMATIC CLOSING OF A MOTOR-OPERATEDGARAGE DOOR [76] inventor: Florian Laiontaine, 10747 Hotel de Ville,Montreal Nord, Quebec, Canada [22] Filed: Mar. 8, 1974 211 Appl. No.:449,269

Primary Examiner]. D. Miller Assistant Examiner-Fred E. Bell [57]ABSTRACT The mechanism comprises two switches: a first thermostaticswitch consisting of three successive adjacently spaced bi-metallicblades; and a second switch having its contacts opened or closed by afirst of said three blades. Movement of this first blade is caused bythe passage of a motor-operating current through a heating elementmounted on the first blade. The second switch is connected to thelatching relay coil in the garage door motor circuit and its actuation,after the garage door has travelled to a fully opened position, ensuresthe automatic return of the garage door to a closed position. Thismechanism enables the garage door to always close after it has beenopened and also to give indication of its imminent closure.

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0 F LATCHWG RELAY 1 SWITCH MECHANISM ENSURING THE AUTOMATIC CLOSING OF AMOTOR-OPERATED GARAGE DOOR FIELD OF THE INVENTION The present inventionrelates to a switch mechanism for ensuring the automatic closing of amotor-operating garage door after the door has travelled to a fullyopened position.

BACKGROUND OF THE INVENTION The popularity of operating a garage doorwith a radio remote control increases everyday. However, thepossibilities of having doors opened by people other than thosepermitted increase also proportionally. This is explained by the factthat remote controls are subject to rigid federal laws which limit theamount of frequencies available for this purpose. Hence, it isrelatively easy for persons not permitted to have access to a particulargarage to find the given frequency for the operation of the garage door.Serious inconveniencies can result in having a door remaining opened ina very cold wheather for example, where severe and costly damages canoccur to the building or articles inside the garage.

STATEMENT OF THE INVENTION It is therefore an object of this inventionto provide a mechanism which will ensure the automatic closing of agarage door once it has reached a fully opened position.

I The mechanism consists in the combination of two interacting switches;the first switch consists of three successive adjacently spacedbi-metallic blades, one of which is provided thereon with an electricheating element for operating the blade. Such thermostatic switch may befound disclosed in U.S. Pat. No. 3,533,039 is-, sued Oct. 6, 1972 to DB.Mundt. The second switch is disposed adjacent the heater carrying bladeof the thermostatic switch and is provided with contacts which areopened or closed depending on whether a motoroperating current passesthrough the heating element. The contacts of the second switch areconnected to a latching relay coil in the motor circuit; when thesecontacts are closed after the door has travelled to a fully openedposition, the garage door motor is energized to return the garage doorto a fully closed position.

DESCRIPTION OF THE DRAWINGS Other objects, purposes and characteristicfeatures of the present invention will be in part obvious from theaccompanying drawings, and in part pointed out as the description of theinvention progresses. In describing the invention in detail referencewill be made to the accompanying drawings, in which like referencecharacters designate corresponding parts throughout the several views,and in which:

FIG. 1 is a front elevational view of a switch mechanism made inaccordance with the present invention;

FIG. 2 is an end view of the switch mechanism shown in FIG. 1; and

FIG. 3 is a circuit diagram for carrying out the operation of the switchmechanism shown in FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENT Referring to FIG. I there is shown aswitch mechanism 10 which consists principally of a thermostatic switch12 and of a second switchld. These switches 12 and 14 are mounted on aniron angle support 16 which includes two contiguous walls 18 and 20.

The thermostatic switch 12 includes three successive adjacently spacedblades 22,24 and 26, each having one end fixedly mounted in a block 28of rigid insulating material, such as 'porcelaine, which is fixedlymounted to the wall 18 by means of a bracket 19. A heating element 30covers a substantial part of the blade 22. The particular constructionand material preferably used for the thermostatic switch 12 are taughtin the above-mentioned U.S. patent to Mundt and will not be repeated inthe present disclosure. Blade 22 is connected to the line voltage, whileblade 24 is connected to a lamp 25 and blade 26 is connected to thegarage door motor 27.

Blade 22 is flat and bi-metallic and tends to curve toward thebi-metallic blade 24 as the temperature raises in the heating element30.

Each end of the blades includes contacts, such as 32, 34, 36 and 38, sothat suitable contact may be effected between blades 22, 24 and blades24 and 26. The opposite ends of the blades are secured in block 28, andthis allows a certain movement for the free ends of the blades.

Although not shown in FIG. I, but schematically represented in FIG. 3,the heating element 30 is ground to blade 22; a metallic connection 40is provided between the heating element 30 and the third blade 26.

Switch 14 includes a metallic blade 42 which is adapted to move intocontact with contact 44 when actuated by the blade 22 of thethermostatic switch 12. Switch 14 includes two connections 48 and 50 forconnection with the coil of a latching relay used for the operation ofthe garage door motor.

Referring to FIG. 2, switch 14 is fixedly secured to wall 20 by means offasteners 52 and 54; fastener 54 is suitably received in a slot 56 so asto allow adjustment of the position of the switch l4"and its blade 42relative to the thermostatic switch 12 or its blade 22.

Although not illustrated in the drawings, the garage door mechanismincludes a series of limit switches which operate to de-energize themotor circuit when the garage door has reached a fully opened positionor a fully closed position; also provided are mechanisms which will stopor reverse the ,door movement when an obstacle is encountered duringoperation. Such mechanisms may be found described in U.S. Pat. No.3,633,313 issued Jan. 11, 1972 to Lucien Lafontaine.

An ON-OFF switch 58 may be inserted in the circuit between switch 14 andthe latching relay coil should the automatic closing feature betemporarily not wished.

OPERATION OF PREFERRED EMBODIMENT When the garage door is in a fullyclosed position, blade 22 is in the rest position shown in FIG. 1 andcontacts blade 42. In this position, however, the motor is not energizedsince a limit switch, which was actuated when the door reached itsclosed position, caused the opening of the motor circuit assuming nowthat the door is opened as resulting from a remote radio signal ordirectly through button actuation, a motor operating current passesthrough the heating element 30 causing blade 22 to bend toward theintermediate blade 24. As blade 22 raises, connection between blade 42and contact 44 is opened. The contact of blade 22 with blade 24 causesthe illimination of the lamp 25 to indicate that the door is beingopened. Depending upon temperature condition, the time taken to blade 22to contact blade 24 may vary by adjusting the relative po sition of theblades 22 and 24. Contact may be accomplished before or after dooroperation has been accomplished. When contact is established between 22and 24, the lamp current does not pass through the heating element.There is provided an automatic door control switch which stops the motorwhen the door has reached a fully opened position. Should the blade 22continue to respond to a raising temperature from the heating element,there will be contact between blades 24 and 25 thereby short-circuitingthe heating element 30 and this is irrespective whether the motor isoperating or not.

The important feature of the present invention is that, once the door iscompletely opened, the return of blade 22 to its normal rest position,either through the motor stopping or the short-circuiting of the heatingelement, results in closing blade 42 on contact 44. This, together withthe actuation of the upper limit switch, will cause the energization ofthe latching relay coil and the operation of the motor in a reversedirection to close the door. Once the door will have reached a fullyclosed position, an automatic door control switch will open the motorcircuit.

It can be seen that, when the light 25 is turned off as a result ofblade 22 separating from blade 24, this is an indication to theiobserverthat the door is about to close in a given lapse 'of time. This timelapse may be varied by adjusting switch 14 on sidewall 20.

Although the'invention has been described above in relation to onespecific form, it will be evident to the man skilled in the art that itmay be refined and modified in various ways. It is therefore wished tohave it understood that the present invention is not limited ininterpretation except by the terms of the following claims' What] claimis:

1. A switch mechanism for ensuring the automatic closing of amotor-operating garage door after said door has reached a fully openedposition, comprising, in combination:

a. a thermostatic switch for providing delayed switch action including:

i. a first bi-metallic blade having an electric heating element mountedlongitudinally thereon; said heating element operating on said bladewhen energized by a motor-operating current;

ii. a second blade adjacently spaced from said first blade for turningon an electric lamp when contacted by said first blade when temperatureraises in said heating element;

iii. a third blade adjacently spaced from said second blade forshort-circuiting said heating element when energized for an excessivelylong period of time;

b. a second switch having contacts normally closed by said first bladeof said thermostatic switch when the garage door is in a fully closedposition; said second switch being connected to a latching relay coiladapted to operate the garage door motor; said contacts opening whensaid motor-operating current passes through said heating element andsaid first blade moves to contact said second blade; said contacts beingsubsequently closed by said first blade when, after the garage door hasreached a fully opened position, said first blade returns to itisinitial contact closing position.

2. A switch mechanism as defined in claim 1, wherein said thermostaticswitch and said second switch are mounted on a support having contiguouswalls; one of said walls supporting said second switch and havingthereon means for adjustably securing said second switch relative tosaid first blade of said thermostatic switch.

3. A switch mechanism as defined in claim 2, wherein the contacts ofsaid second switch include a movable blade in normal contactingengagement with said first blade of said thermostatic switch.

4. A switich mechanism as defined in claim 2, wherein said one of saidwalls being provided with a slot therein for the adjustment of saidsecond switch relative to said first blade.

1. A switch mechanism for ensuring the automatic closing of amotor-operating garage door after said door has reached a fully openedposition, comprising, in combination: a. a thermostatic switch forproviding delayed switch action including: i. a first bi-metallic bladehaving an electric heating element mounted longitudinally thereon; saidheating element operating on said blade when energized by amotor-operating current; ii. a second blade adjacently spaced from saidfirst blade for turning on an electric lamp when contacted by said firstblade when temperature raises in said heating element; iii. a thirdblade adjacently spaced from said second blade for short-circuiting saidheating element when energized for an excessively long period of time;b. a second switch having contacts normally closed by said first bladeof said thermostatic switch when the garage door is in a fully closedposition; said second switch being connected to a latching relay coiladapted to operate the garage door motor; said contacts opening whensaid motor-operating current passes through said heating element andsaid first blade moves to contact said second blade; said contacts beingsubsequently closed by said first blade when, after the garage door hasreached a fully opened position, said first blade returns to itisinitial contact closing position.
 1. A switch mechanism for ensuring theautomatic closing of a motor-operating garage door after said door hasreached a fully opened position, comprising, in combination: a. athermostatic switch for providing delayed switch action including: i. afirst bi-metallic blade having an electric heating element mountedlongitudinally thereon; said heating element operating on said bladewhen energized by a motor-operating current; ii. a second bladeadjacently spaced from said first blade for turning on an electric lampwhen contacted by said first blade when temperature raises in saidheating element; iii. a third blade adjacently spaced from said secondblade for short-circuiting said heating element when energized for anexcessively long period of time; b. a second switch having contactsnormally closed by said first blade of said thermostatic switch when thegarage door is in a fully closed position; said second switch beingconnected to a latching relay coil adapted to operate the garage doormotor; said contacts opening when said motor-operating current passesthrough said heating element and said first blade moves to contact saidsecond blade; said contacts being subsequently closed by said firstblade when, after the garage door has reached a fully opened position,said first blade returns to itis initial contact closing position.
 2. Aswitch mechanism as defined in claim 1, wherein said thermostatic switchand said second switch are mounted on a support having contiguous walls;one of said walls supporting said second switch and having thereon meansfor adjustably securing said second switch relative to said first bladeof said thermostatic switch.
 3. A switch mechanism as defined in claim2, wherein the contacts of said second switch include a movable blade innormal contacting engagement with said first blade of said thermostaticswitch.